Small satellites grow in popularity

Apr 27, 2009

Nations large and small around the globe are placing increasing reliance on small satellites to ensure they have a mechanism in space to provide timely intelligence and strategic communications for national security purposes, reports Aviation Week.

Most nations, particularly small countries, lack the resources, technology and money to create and maintain constellations of orbiting satellites. Smaller, less-costly satellites weighing 500 kg. (1,100 lb.) or less are emerging as practical options. In recent years, large countries, including the United States, as well as small ones have recognized the benefits of these platforms.

There are four categories of small satellites: Minisatellites weigh 100-500 kg.; microsatellites 10-100 kg.; nanosatellites 1-10 kg.; and picosatellites 0.1-1 kg. Mini- and microsatellites are becoming more common in space programs, for the advantages they provide in speedy launch schedules and economy. Nanosatellites are beginning to be tested and deployed, while picosatellites are largely experimental.

One nation that is actively developing small satellites is Israel, which has maintained an indigenous space capability since 1988. Satellite surveillance is particularly critical for Israel, which faces strategic threats from hostile neighbors and from countries as far away as Iran.

Minisatellites serve Israel well but the space program is looking at more sophisticated concepts. One calls for launching microsatellites into low Earth orbit in constellations that would provide continuous target coverage. These vehicles will be lofted on demand by rockets carrying single or multiple satellites. Scientists are studying the characteristics that will be required to achieve this, including electronic and electromechanical miniaturization, ion-driven thrusters, lightweight structures, laser communication and compact imaging.

Prof. Isaac Ben Israel, director general of the Israel Space Agency, outlined the military benefits of microsatellites and nanosatellites.

“These future spacecraft will offer unprecedented tactical use of space assets,” Ben Israel said. “Space has served military operations at the strategic level, mainly for early-warning and long-range intelligence surveillance in airpower mission planning. However, small satellites could revolutionize warfare, opening new dimensions and opportunities for tactical commanders by providing timely intelligence for pre-mission planning.”